The invention is in the field of liquid crystal display (LCD) devices, and relates more particularly to the reduction of unwanted reflections from inter-pixel areas of such devices.
Reflective LCD devices per se are known to those of ordinary skill in this art. Examples of such devices, and in particular active matrix devices, are shown in U.S. Pat. Nos. 4,239,346 and 5,056,895, as well as in co-pending U.S. patent application Ser. No. 08/995,824, filed concurrently herewith and in which the present inventor is a co-inventor. With reference to the following description, familiarity with conventional features of such devices will be assumed, so that only features bearing on the present invention will be described. Accordingly, the content of the aforementioned patents and application are incorporated herein by reference in their entirety, in the interest of brevity.
A problem prevalent in prior-art devices is that, in the activated or dark state, light may be reflected in light transmissive regions between the pixel electrodes, due to the presence of a reflective material beneath the light transmissive regions between the pixel electrodes. Such light is reflected back in the viewing direction, and reduces the contrast of the image being displayed because bright regions are created in regions between reflective pixels which are in the dark state. While this problem could be solved by a light shield placed on the upper glass layer of the LCD device, precisely aligned with the underlying inter-pixel regions, such a solution would be costly, complex, and would demand a very precise alignment of the light shield with the light transmissive or inter-pixel regions.
Accordingly, it would be desirable to reduce or minimize light reflection in the inter-pixel areas of an LCD device without the need for a costly, high-precision and complex light shield.